1. Field of the Invention
The present invention relates to a secondary battery system using a secondary battery.
2. Description of the Related Art
There is a conventionally known secondary battery system which supplies electric power by using a secondary battery. Such a secondary battery system is used, for example, to compensate for electric power at power receiving points (for example, see “The January issue of Monthly Energy”, The Nikkan Kogyo Shimbun, Ltd., Dec. 28, 2004, pp. 82 to 84).
However, when electric power is supplied by using a plurality of secondary batteries, operation of a secondary battery system need be limited depending on residual power levels of individuals of the secondary batteries, in some cases.
Therefore, the secondary battery system sometimes cannot efficiently be operated due to the residual power of the individual secondary batteries.